plate 84 viral diseases of the digestive and lymphoid organs
TRANSCRIPT
Plate 84
Viral Diseases of the Digestive and Lymphoid Organs
Viral Gastroenteritis
• Viral gastroenteritis: inflammation of stomach and intestines
• Often called “stomach flu”, although it is not caused by the influenza virus
• Symptoms: primarily diarrhea and vomiting, but also headaches, fever, and stomach-ache
Yellow fever
• Sometimes known as “yellow jack” or “black vomit”
• Called “yellow fever” because of the jaundice that it causes
• RNA icosahedral (Flaviviridae family) virus
Symptoms• 3-6 days of incubation, then
3-4 days of fever and muscle pain
• Most patients improve and symptoms disappear
• 15% of patients enter a 2nd toxic phase:– Bleeding from mouth, nose,
eyes, and/or stomach– Kidney failure– Jaundice– 50% mortality in 14 days
• No cure, just treatment for symptoms
Symptoms
• Jaundice – “yellowing” of skin and eyes
• Bile passes from the gallbladder and/or liver into the bloodstream
Transmission
• The virus is transmitted via mosquito bites
• Virus passes from the mosquito’s saliva to the human bloodstream
• Can also pass from monkeys to mosquitoes to humans
Aedes aegypti mosquito
Transmission• Estimated 200,000
cases and 30,000 deaths per year worldwide
• Vaccine is very effective
• Cases have increased over the past 20 years due to urbanization, deforestation, and climate change
Philadelphia• Summer 1793, French refugees (some who had
Yellow Fever) fled the Haitian Revolution and came to Philadelphia
• By November 1793, about 5,000 Philadelphians had died (more than 10% of population)
• Summer 1794, Yellow Fever returned, but not as severely, and also in 1796 and 1797
• Another severe epidemic came in 1798, killing 1,292 Philadelphians
• At the peak of the 1798 epidemic, all but 7,000 residents had left the city
Dengue Fever
• Also known as “break-bone” fever
• RNA icosahedral (Flaviviridae family) virus
DF - Symptoms• Dengue fever has symptoms
which can be very similar initially to flu
• Most people suffer from headaches and fever, some get muscle and bone pains
• An infected person can feel tired for up to three months, but will not usually need treatment
• May lead to Dengue Hemorrhagic Fever (DHF), which is potentially lethal
DF - Symptoms (continued)
Itchy rash. Everywhere I had ever been injured hurt again. Achy like the flu but worse. Exhausted. Literally took months to regain full energy and stamina.
DF - History
• Dengue fever originated in primates and “jumped” to humans 100-800 years ago
• Because of disruption from WWII and international trading of cargo, the Aedes mosquito has spread to tropical regions around the world
• Not until 1981 that the disease became problematic in Latin America and the Caribbean
DF - Location
• 40% of the world’s population live in areas where they are at risk for dengue transmission
• WHO estimates that there are 50-100 million infections a year and 22,000 deaths
• http://www.healthmap.org/dengue/index.php
DF - Treatment
• There is no cure for dengue fever nor is there specific medication for it
• Patients should rest, take pain-relievers, and drink plenty of fluids
DF - Transmission
• Dengue viruses are mainly transmitted by the bite of infected Aedes aegypti mosquitoes
Mononucleosis
• The “kissing disease”• Epstein-Barr virus
(human herpesvirus 4)
Mono - Symptoms
Mono - Symptoms
Mono Symptoms - Swollen Tonsils
Mono - Transmission
• Virus spread through salivary drops
Hepatitis A
• RNA enterovirus (hepatitis A virus – HAV)
HAV - Symptoms
• Can cause:– Swelling of the liver– Jaundice– Fatigue– Loss of appetite– Diarrhea
HAV - Transmission
• Spread primarily by food or water contaminated by stool from an infected person
• Eating food prepared by someone with HAV who did not wash their hands after using the bathroom
Hepatitis B
• Hepadnavirus (hepatitis B virus – HBV)
HBV - Symptoms
• Short-term HBV resembles symptoms of the flu
• Possible symptoms include fever, dark urine, vomiting, and jaundice
• Long-term HBV (chronic HBV) lasts a lifetime and can lead to scarring of the liver, liver failure, and liver cancer
• Interferon can be used to slow the virus from damaging the liver
HBV - Transmission
• HBV is spread through contact with blood, semen, or other body fluids of an infected person
Hepatitis C
Symptomsjaundice, fatigue, dark urine, nausea
Long terminfections (55-85%), leading indication for transplant,
Info.No vaccine, interferon, do not share personal items, rarely STD
Hepatitis D
Symptomsjaundice, fatigue, tea-colored urine joint pain
Long Termmore sever acute disease & risk of failure
Info.acquires along with HBV
Hepatitis E
SymptomsJaundice, dark urine, loss appetite, fatigue
Long Termno long term often seen in pregnancy
Info.highest among 15-40 yo, contaminated water